\nonstopmode \input expl3-generic \relax \ExplSyntaxOn % -*- expl3 -*-

\cs_new:Nn \svend_gcd:nn
{
	\int_compare:nNnTF {#2} = { 0 } {#1}
		{ \svend_gcd:ff {#2} { \int_mod:nn {#1} {#2} } }
}
\cs_generate_variant:Nn \svend_gcd:nn { ff }

\int_new:N \l__svend_tmp_int
\cs_new:Nn \svend_reduced:nn
{
	\int_set:Nn \l__svend_tmp_int { \svend_gcd:nn {#1} {#2} }
	{ \int_eval:n { #1 / \l__svend_tmp_int } }
	\over
	{ \int_eval:n { #2 / \l__svend_tmp_int } }
}

$$ \svend_reduced:nn {278922} {74088} $$

\bye
